Question about Fibre install

[#1]

Hi guys i have just signed up for unlimited fibre and hopefully will up and running on 5th March if all goes to plan.
i have a question about the install i hope you can help me with, I understand that the modem is installed near the master socket that's not a problem, My PC and where the router when it arrives will be installed in a room upstairs around about 25m away from where the master socket / modem will be installed, I also understand that the modem and the router need to be connected together.
this is where i'm a little unsure, I made the request for the data extension cable when i placed my order just to be safe, but i believe its a Cat 5 Ethernet cable that connects them together if so is this included in the install by that i mean one at the length i require or do i have to purchase that myself it's no problem if i do  I just dont want to wast money on getting one if it's not needed.
thanks for any info       

[#2]

does no one have an answer ? 

[#3]

The data extension will effectively move the BT Modem from the master socket location to wherever they install it.
You can also install your own CAT5e cable between the modem and wherever you are locating your router - this is the preferred route to take as it keeps the modem as close to the master socket as possible hence maximising the speed.
Not sure if the data extension cable BT provide is a full CAT5e cable so you might want to err on the safe side and sort one out before install date.
Personally I put a CAT5e socket on the wall by the modem, ran CAT5e cable to where my switch / router was and put another socket on the other end. I can either patch the master socket to the CAT5e socket and remote locate the Modem or have the modem by the master socket and route the Modem output through to my router via the CAT5e sockets.
Hope that makes sense.

[#4]

Homeplug (Powerline) is the easy option!

[#5]

thanks for the replies guys i think i'll get myself a Ethernet cable before the install date just in case,  i can always keep it as a spare if the engineer has one long enough thanks again